The present invention relates generally to needle covers, and more specifically to disposable hypodermic needle covers designed to minimize accidental needle sticks and enhance ease of use.
In using a disposable syringe, particularly one fitted with a hypodermic needle, the syringe is removed from a sterile package, the conventional needle cover is grasped and removed using one hand to hold the syringe and another to hold the cover, the needle is inserted into the serum bottle, the bottle is inverted and the piston of the syringe is pushed inward, therein forcing air into the bottle. With the bottle inverted the syringe is filled by retracting the piston until the desired quantity of serum has been drawn into the barrel of the syringe. The syringe is then recapped, using the previously removed needle cover, and positioned on a tray for conveyance to the patient's room. Prior to the actual injection the syringe has to be uncapped again, and then, following the injection, it is recapped, for the third time, prior to disposal. Typically, the spent syringe is disposed of in a dedicated disposal box, which is designed to prevent the syringe from being utilized again, by authorized or unauthorized personnel. The outlined procedure for using a syringe creates a significant number of opportunities for the administering medical personnel to accidentally stick themselves with the needle. The syringe disposal box can be particularly onerous as it can be a source of multiple uncapped needles. Once a shot has been administered there is much less perceived necessity for diligently recapping the needle. Not infrequently, the syringe is not recapped prior to disposal, and someone, subsequently discarding a spent syringe in the syringe disposal box, has an excellent chance of accidentally sticking themselves.
Sturman in his U.S. Pat. No. 4,863,435 cites a report by Biomedical Business International that estimates that there are more than 800,000 accidental needle sticks each year. Sturman discloses a safety hypodermic syringe, wherein following the injection, the tip of the needle is covered by releasing a spring fitted with a cap.
Netherton's U.S. Pat. No. 4,900,309 discloses an alternate solution to preventing needle sticks. In his invention, the entrance of the needle cover is fitted with a flange, wherein the flange serves as a shield.
Other related prior art includes Giuffre's U.S. Pat. No. 4,880,413 funnel shaped needle cover, and Strauss U.S. Pat. No. 4,664,654 which discloses an "Automatic Protracting and Locking Hypodermic Needle Guard", that has a sliding member that can be locked in place to protect the point of the needle.
The instant invention is a needle cover for a disposable hypodermic needle mounted on a syringe, wherein the cover can be removed and repositioned with one hand without ever having to come near the point of the needle. The swing-away needle cover is removed using one finger by pulling down a lever arm attached to the cover, which causes the cover to rotate away, therein exposing the needle. The cover is repositioned by reversing the process. The cover, during procedures requiring exposure of the needle such as filling or injecting, is rotated approximately perpendicular to the axis of the needle, well out of the way of the on going activity. The needle cover snaps into place in the coaxial and in the perpendicular positions. The swing-away needle cover, at first glance, appears to be substantially like a conventional needle cover. It is comprised of a resilient plastic like polyethylene or polypropylene and presents a relatively narrow profile like a conventional needle cover, unencumbered by large shields or mechanically complex attachments. The swing-away needle cover rotates away from the needle, where the needle hub is the pivot point of rotation. The cover is substantially a tapered tube with a longitudinal slit, the slit being sufficiently long and wide to permit the free passage of the needle through the slit. The tapered tube serves as a protecting sleeve covering and sheathing the longitudinal length of the needle, wherein the attenuated end of the tapered tube, covering the tip of the needle, is sealed with a closing cap. At the other end of the tapered tube, covering the hub of the needle, the longitudinal slit widens to an longitudinally elongated hole having a narrow radius of sufficient width to permit the needle end of the hub to fit through, with little or no distortion of the hole. The opposing side of the tapered tube has a partially open hole, wherein the entrance to the hole is constricted by a pair of tabs. Once past the tabs the radius is sufficiently wide to permit the syringe end of the hub to fit through. The constricting tabs prevent the needle cover from rotating unless sufficient force, applied against the lever arm, is supplied to distort the tabs wide enough to let the hub pass through. The partially open hole faces toward the syringe. The tapered tube has a pair of bearings located in the wall of the tube adjacent to the hub. The bearings, which can be little more than perforations in the wall, have an axis which is perpendicular to the plane of rotation of the needle cover. The bearings are attached to the hub through a hinging member that is substantially a pair of axial elements emanating radially from the hub or a sleeve on the hub.hinged perpendicular to the longitudinal slit. The hinging member enables the needle cover to rotate away from the tip of the needle, in a plane defined by the longitudinal slit and the needle. When the tapered tube is forced to rotate from the coaxial position toward the perpendicular position, the tabs of the partial opening initially resists the deflection, and only when adequate force has been applied to cause the hub to press open the tabs does the tapered tube move away from the coaxial position. As the angle of deflection from the coaxial position increases the needle emerges from the longitudinal slit, and the needle end of the hub moves into the elongated hole which is contiguous with the longitudinal slit, and the syringe end of the hub moves past the tabs and into the central portion of the partially open hole. The tabs act as a kind of safe guard lock, preventing the needle cover from moving either into or out of the coaxial or perpendicular positions unless forced by pressure on the lever arm. The tapered tube is fitted with an upwardly curved lever arm on the side opposite the longitudinal slit. The lever arm is distal to the needle end of the hub, when the cover is in the coaxial position. The lever arm is constructed so as to be of sufficient length and strength as to enable the user of the syringe to pull the tapered tube out of the coaxial position and into the perpendicular position, and vice versa.